Detection of metastatic medullary thyroid cancer with ¹³¹I-MIBG scans in Sipple's syndrome

While ¹³¹I-meta-iodobenzyl guanidine (¹³¹I-MIBG) scanning has made possible the scintigraphic visualization of pheochromocytoma and neuroblastoma, an accumulation of this agent has recently been reported in medullary thyroid cancer. We present the case of a patient with Sipple's syndrome (multiple endocrine neoplasia type IIa), in whom we were able to identify distant metastases and local invasion of medullary thyroid cancer as well as primary thyroid tumour and right adrenal pheochromocytoma, using ¹³¹I-MIBG scans. This case highlights the usefulness of ¹³¹I-MIBG in the detection of metastatic medullary thyroid cancer and suggests that this agent may also be of therapeutic use in the treatment of tumours.